Duplicating apparatus



" y 3'1". 19.39- A. MARCHEV 2,145,729

DUPLICTING APPARATUS Filed Maty 29, `1936 '7 Sheets-Sheet 1 Y f l- L Jan. 31, 1939. A] MA'RCHEV 'DUPLICATING APPARATUS l Filed may 291936 I '7 Sheets-Sheet 3 6% W @Ma/1 Jan. 3l, 1939. A. MARcl-,nvy

` DUPLICATING APPARATUS Filed May 29, 1936 7 Sheets-Sheet 4 Jan. 31, 1939. I A, MARCHEV 2,145,729

DUPLICATING APPARATUS 3l, 1939. A. MARCHI-:v

A DUPLCATING APPARATUS Filed May 29, 1936 A 7 sheets-sheet 7 Jan. 31,

` P-.li'rlazirrA osi-*ICE 2.14am n y limitiamo mana'rus n ,n ummm., animtonia Y to, Incorporated, Chicago, lll., aeorpontion ofy Welt , Application May zt, lass, soi-m No.' 32,40: y1s claims. (ci. 1v1-'132i The invention relates to duplicatingapparatus and is'particularly adapted to be'embodied in ,Y duplicating machinesof the type'wherein master sheets havingdata typewritten thereon in reverse are secured to ylajlbi'ixiting or duplicating 'and are brought into contact with copy sheets ywhich ,have been previously' moistened with a solvent for the ink on the master sheets. However, the invention is limited to this parlo-tlcularuse only to thev extent indicated in the i appended claims;

object of the? invention is to provide a machine ofthe type described which ,is simple in construction, inexpensive and efficient.

" 15' Another object of theinvention is to provide improved means to clamp the mastersheets'to the duplicating or printing drum.

Other objectsk and ladvantages will become apparent as the following description progresses,

` 2 reference being had to the accompanying draw- "iings, wherein` j ,ll is a plan view cfa duplicating machine which embodies the invention. f n

` Fig. 2 is la section taken substantially on line, 252-2oflde21.

` lllg. 3 vis'an enlarged fragmentary section taken `onlinel3of Figfl. r f

f.1ig.' 4 vris an enlarged fragmentary section taken on` the same line as Fig. 3 but .showing 30k certain parts .ofv the mechanism in [changed Fig. 5 is a section taken on line 5;-5 of Fig. 3. 111g. l6 Visa section' taken on lin'e S- Bof 5. Fig. 'l isan enlarged fragmentary planv view, partly broken away, of the machine.

iik is a somewhat diagrammatic' section taken on line 8-8 of Flg. 9. l Fig. y9 is a section taken on line S-Bfof Flg..8. Fig. l0 is a fragmentary section* taken on line o u--ll ors-1g'. 3, and

. Figjll is an enlarged fragmentary section takenonlin'eII-IlofFig.2.` l

Referring for the present to Figs.'l to'5, inelusive, 'fit willzbe noted that the improved du` 4;, plicatlng machiriecomprises two side frames II and I2 which are preferably formed'from sheet metal 'and are re-enforced by plates I4 secured toxthe inner surfaces of the side frames. The \side frames are secured to each other' by a sheet 50 metal bracketl .li andf-by several shafts which v y extend between y'the side frames.

y between the side frames' II and I2 is 'afduplicatingor printing drum I1 fixed to a Il which has its ends iournalled in ball 55 me l! mqiltedfin the frames Il and I2.

(Fig. 5.) a 'The arma l1l comprises a subseantwly cylindrical wall 2I and end walls 22 and 23. Journalled in the end walls 22 and 23 is a shaft 24 upon 'whicha pluralityof clamping or gripper members 2i are pivoted. Pins 26 projecting from 5 the shaft 24 project into slots 21 formed in the gripper members and limit angular displacement of the gripper' members relative to. the shaft. Springs 2l wound`around the shaft 24 yieldingly urge the grippers 2i in a clockwise kdirection 10 (Fig. 8) relative'to theilongitudinal axis of the shaft 24. The free ends of the grlppers 25 project into a slot 2l formed in! the cylindrical wall 2|. An inclined surface 20 provided along one edge` of the slot 2l co-operates with the free ends '15 of the grlppers 25 to clamp master sheets to the drum I1. Oneof the master sheets is shown in Fig. 8 and is identifiedby the reference character 3l. It will be noted that one edge of the sheet #I is clamped between the surface l0 and zo the grippers 2l. :The end walls of the drum I1 arey apertured asat 22 to facilitate the task of assembling the grlppers 25 and the shaft 24 with the drinn.

Co-operating with the drum` I1 to press the copy sheets against the master sheetsy is a platmi roller I5, preferably formed of rubber, the roller 35l being mounted` on a shaft Il which has its ends journalled inball bearings $8 mounted in arcuate grooves 3 formed in levers 40. The levers 4l are mounted on,pins 42 which project from the side framesv II and I2. The lower ends of the levers 4I are apertured to receive set screws 43 whichare" adjustably secured to the 35 levers bynuts'44. Theheads ofthe set screws 4I abut against cams 4l fixed to a shaft 46 which is journalled in the side frames II 'and I2 and is provided at one end with a knob 41 so that the shafty 4C may be displaced angularly by the oper- 40 ator. The set screws 43 may be adjusted so that the platen roller Il' exerts the desiredk pressure upon the copy sheetswhile they are being pressed against the master sheets.` If, at any time the operator desires to change this adjustment it is' 45 only n s s: to rotate" the knob 41 so that the cams 45 will angularly displace the levers 4l in the desired direction to decrease or increase the pressure of the platen roller 25 fupon the duplicating drum I1. yAejtray Il is provided to receive the 50.

the pins 42. fIntermediate'its ends, the'tray 5I Il rings 63 which are mounted in arcuate recesses provided in one end of each of two levers 60, the levers 60 being journalled on a shaft 85 which extends between the side frames and I2. Thel other ends of the levers 60 are providedwith a plurality of notches 66. Engaging a notch 66 in each of the levers 60 is one end of one of a plurality oi' springs 61 which have their other ends secured to pins 68 projecting from the side frames I| and I2. Obviously, the springs 61 yieldingly urge the roller 51 againstthe composition roller 60'and the pressurewith which the roller 51 is urged against the composition Y roller 80 may be adjusted by selecting one or anstub shaft 98.

other oi' the notches 66 in each lever 60 as the point to which the associated spring 61 should be attached. o,

The shaft 6| has a recess 10 in each end (Fig.

10). A bushing 1| disposed in the'recess is jour` nalled on one end of a pin 12 projecting from the adjacent side frame or I2, the bearing portion of the pin being of reduced diameter. The pin is secured to the adjacent side frame by a block 10 secured to the side frame byscrews 15. Fixed to the blocks 10 and extending between them is a'guide plate 11 which prevents the copy sheets from being drawn around the composition roller 59. At one end of the shaft 6| a gear 18 is secured (Fig. 2). The gear 18 meshes with a pinion-19 which meshes, in'turn, with a gear 80 mounted upon one end of the shaft |8 and constrained to rotate with the drum |1 by pins.8| (Fig. 5). The pins 8| also project through a gear 83 mounted upon the shaft I8. The gear 83 meshes with a pinion 85 fixed to one end of a' shaft 88 which is journalled in ay bearing 81 secured in the side frame I2. The outer end of the shaft 86has a crank armor lever 88 secured thereto whereby the operator may rotate the shaft 86 so that the pinion 85 will rotate the gear 83 and the drumIT. Obviously, when thedrum |1is rotated, the gear will drive the pinion 19 and it, in turn, will drive the gear 18 which drives the composition roller 60. The roller 51 frictionally engages the composition roller 60 and therefore will be driven in unison with the composition roller 60. g

Secured to the end wall 22 of thejdrum i1 by bolts 90 is a cam 9| which has la dwell92. The dwell 92 is a 'portion of a cylindrical surface having its longitudinal axis coincident withthe axis .of rotation of the shaft |8. The dwell 92 is only interrupted by a single depression 94. Cooper ating with the cam 9| is a roller 96 adapted to ride upon the dwell 92 and to drop into the depression 98 when the depression is alined with the roller. The roller is mounted on one end of a lever 95 which is pivoted intermediate its ends on a stub shaft 98 projecting from the side frame The other end of the lever 95 is engageable with a lever 91 which is also 'pivoted upon the The roller 96 is vurged against the cam.9'| by a compression spring 99, one end of |00 fixed to the inner side of the reenforcing plate |0 provided for the side frame I2. In Fig. 2, the roller 96 is shown resting in the depression 90. It will be readily understood that when the shaft I8 is rotated in a counter-clockwise direction the roller 98 willride up on the dwell 92 andwill displace the-lever95 in a clockwise direction (Fig. 2) against/the action of the spring ss and the lever 95v will displace the lever 91 angularly in a clockwise direction (Fig. 2). The lever 91 actuates means for supplying a solvent to means for moistening the copy sheets as they are advanced to the composition roller 60 and the roller 51, these rollers being feed rollers to feed the copy sheets between the drum I1 and the platen roller 35. The solvent supplying means preferably comprises a tank or reservoir I 02 disped adjacent the sheet metal bracket I5. Extending through the reservoir |02 is a cylindrical member |03 having a central bore |00 which is closed at its lower end. The cylindrical member |03 is of reduced diameter at its lower end, the reduced portion ,projecting through the bracket I5 and being secured thereto by a nut |05. Ports |06 in a cylindrical member |03 permit the bore |00 to communicate with the interior of the reservoir in the bottom portion thereof. Ports |01 in the cylindrical member |03 permit the bore |00 to communicate with the-interior of the reservoir |02 in the upper portion thereof. Slidably journalled in the lower end of the bore |00 is la piston I I0 which is connected to the Afree end of the lever 91 by a piston rod I||. It will be noted that the rod I|| projects through a` bushing ||3 which closes the `upper endof the bore |00. Nuts ||5 screw-threaded upon the upper end of the piston rod rest upon an arcuate surface H6 provided upon the lever 91. Obviously, the nuts ||5 can be manipulated to bring the piston till into adjusted positions with respect to the lever 91. A spring ||8 disposed in the bore |06 extends between the bushing ||3 and the piston I|0 and urges the piston downwardly. Obviously. when the lever 91 is displaced in a clockwise direction (Fig. 2) as described above, the piston H0 will be drawn upwardly. vThe construction is such that therpiston will be drawnabove the ports |06 so that the solvent may iiow from the interior of the reservoir |02 through the ports |06 and into the lower end of the bore |00. Then when the roller 96 again dropsinto the depression 90, the spring ||8 will drive the piston IIO downwardly to drive the solvent from the lower end of the bore |00 into a tube |20 which `communi,

cates with the bottom end of the bore 00. The tube |20 has one end seated in a sleeve |2|. Disposed in the sleeve |2| is a ball |22 which cooperates with the adjacent end of the tube |20 and with a spring |20 to form acheck valve which prevents the solvent from flowing from the sleeve 62| back through the tube |20 to the bore |00. The sleeve 2| communicates through a tube |21 with the means for applying the solvent to the copy sheets. l t

Secured to the lever 91 by screws |39 is an arm |3| provided with a roller |33 which rides upon a cam |39, the cam,v |38 being fixed to a shaft |35 journalled in the side frames i and i2. The cam |30 may be rotated from the position 'wherein it is shown in Fig. 2 to another position `v:a gradual rise or increa inradius so that the. i0l

amount of solvent deliveredto the be adjusted accurately. t v M .--..'lheupper `endfof they tube |21eommunicates Y with a vchamber-|00y which communicates with tube1l20 can atmosphere-fromlashort-tuhe Illing. 2). is

- ber m ist tubeuamm tube uz eommumv(':ommunicatingwith the lower end of the chamcat with a chamber I provided in a housingdl having a coverplate' |00; the ilowfof ingy controlled by a valve mechanism'designated seneraliyby `the reference character |41.' Dis- Dowd-in th'elower portion of the chamber I is n s ifeltrpsmua one lend'` orwmcn contacts a felt strip# illhavin'g a Vfold IlIj andfa substantially '.vertically extending 'portion |02. 'Any 1 solvent collecting in the lower portionv of the` chamber drainsback into thezreservoir'l02 through a tube. |002 Thefolded portion III of the felt4 r strip |00 engages the composition` 00 `and transfers the solvent lfrom the chamber to the composition roller 00. Whenthecopy sheets pass'between thecomposition roller 00 and the roller 01v the upper facesof thecopy sheets aremoistened 'with the solvent, which solvent is preferably alcol hol with or.- without other liquid so1vents.` The f yhousingxl I Il is"urgedyieldingly toward' the com- .positionroller 00 sothat the folded Aportionliil of @the felt strip willfconstatly engage .the composition-roller. Thehousing' |00.' the valve inech- I`01,ithe felt'pad |00, thefeltstrip |00 and fthe `mechanismfmounting the housing |00 in the manner described in the improvedmachine are all described indetail in theco-pending lspplication,r

',be described in detailinthis application. y lWhen the machine `is to be .placed in operation,

the copy sheets are preferably placedlupon a feed :table |00 which has downwardly'ex'tending side o lfianges '|0I (Figs. 2 and 11).""Secured to the side [frames and |2"arez"shaped brackets |03 whichyhave laterally extending-lugs- |00 at their lforwardedges. Slots Informed in the Z-shapedv brackets mare adaptedtovreceivebars |61 rss- 'tenedvtn the outer .sides of the ang IOI, the

rconstruction beingsuch that* timetable 1001s'.

simply/displaced towardfthe machine with the bars V|01 in horizontal with the slots |.00Juntil kthe bars vengage the endsofl the slots yengage thefbottomv surface` of the table |00 when Y fthenotches I1I are engagedbythe rod |10.. In-

l termedistethenomhesi'll andthe mns in, the

levers '|12 are provlded-withviinger pieces |15 which may be pressed upwardly .by the operatori to disengagethe `notches|1| lfromthe rod |10 vwhenfthe operator desires to remove the table |00 from themachine. 1

.70 yl--shaped'suide adsolvent from meltube m vto me meer lu (be- ":Kokayandthereforethis construction need not 'fimtablyonthetopsurfaoeofthetablei (Figs. l and 2). 'lhe guide members have downprojecting pins I0| which ride in slots |02 provided in the .table |00. Springs |00 wound around thepins |0| cause thebottom surfaces of the guides'I00 to engage the top surface `of the table |00 with sumcient pressure so that the guidemembers will not be displaced acciden- 1 tally but must be'displacedby the operator. :Ob-

viously, the guide members may-be `adjusted to aline the copy sheets with the masterv on the drum I1. v

As best shown in llgs. 2, 31nd 4, the forward end of the tableVI 00 is provided with vaninclined portion'i 01 which terminates adjacent the junction point between the compodtion roller 00 and its co-operating roller 01. This construction' insures that the copy sheetswill be advanced properly-to these feed rollers.` It is understood; of course,r thattthe feed rollers 00 and l1 advance the copy sheets to the junction` between the duplicating `drum I1 and thmplaten roller 30 and y that the copy sheets' passbetween the drum I1 f and the platen roller y00. v

In'Flg. 3, the drum`|1-is in the position in whi a master sheet 0I clamped yto it is in registry with the remaining mechanism of the machine so that when a copy sheet' is then advanced by the feed rollers 00 and 01 and the machine is operated by rotating the crank arm 00, the copy sheet will come into ,registry with the master sheet and the data on-the master sheet `will leave a correspondingimpression upon the copy sheet. It will be noted that in Fig. 3, the Vroller 00 engages the depression 94. Assuming that the operator has a stack of copy Sheets on the feed table |00 and is voperatingthe machinefitwill be readily understood that the operator will feel each time the roller 00V-r drops into vthe depression 00 and will y permit .the machine to come to a complete stop until a copy sheet has been advancedl to the feed rolls sothat when the machiner is again set-in operation, theA feed rolls will advance the copy r`sheetto have it register with the master sheet.

,Toone end roi? the shaft 20 Awhich carries the grippers 20, a lever 200 is pinned intermediate its ends. f One end of the lever 2001s provided with a pin,20 I to which one `end of ka. tension spring 202 is secured, the other endof the spring 202 being secured to `a. pin 203 projecting from a lug 200 formed integral with the drum I1. The other end of the lever 200 is engageable by the free end of a lever 200fwhich is pivoted onapin 200 proiecting from the frame I I. A, slot 201 formed in thefree end yof the lever 205 accommodates a pin 200 xedto ahand Alever 2I0 which lis pivoted on a pin 2| I-v projecting from the frame II. The hand lever 2 I,0 is provided with a handle member A2I0. When the parts described in the preceding paragraph are in the positions-in which they are illustrated in Fig. 3, the lever 200 is not in the vicinity of the lever 200 and therefore is not en- Ygageable'vvith it. 'Ihis is the position of the varivcrus parts when'the roller 00 rests in the depression 00. However, when it is desired to replace fthemaster sheet 3| with a new master sheet 3|, the drum is rotated so that a slot 2|5 formed in oneedge of the cylindricalwall 2| oiwthe drum I1 registers with a roller 2I1 journalled on a pin 2I0 which projects from thelever 200. The operatorthen holds the crank member 00 stationary and'displaoes the hand lever 2 I 0 from the position l`wherein it is shown -iny Fig. 3.y to the position wherein it is shown in Fig. 4 `so that the lever 205 displaces the rol1er`2|1 into the slot 2|0 and the drum i1 is held against rotation. Simultaneously with; the movement kof the roller 12H into the slot 2li, the lever 205 engages the lever 200 and displaces it from the position wherein it is shown in Fig. 3 tothe position wherein it is shown in Fig. 4,-so that the shaft 2l is displaced' angularly in a counter-clockwise direction (Fig. 4) When the shaft 24 is displaced in this direction, the grippers 25 are displaced fromthevposition wherein they are shown in Fig. 3 to the position wherein theyv are sh'own in'Fig.4 so that the old master sheet 3i is released. Theoperator then removes the old master sheet and replaces it with a new one, whereupon the lever 2I3 is returned `to the position wherein it is shown in Fig. 3 so that the spring 202 will displace the lever 2li, the shaft 24 and the grippers 25 ina clockwise direction (Fig- 4) to clamp the new master sheet in piace upon the drum. The machine 'is then ready for use and copy sheets may be fed to the feed rolls one by one to obtain copies of the data on the master sheet.

The operation of the machine is apparent from 'the 'above descriptiomBriefiy, a master sheet is made by placing a sheet of paper ina typewriter with a carbon sheet against the back surface of the sheet of paper. .The datum is then typewritten upon the sheet of paper and it appears in reverse on the rear 'side ofthe paper. The master sheet is then clamped on the drum Il with the writing in reverse facing outwards. The solvent employed is one which will dissolve' the carbon.

The copy sheets are fed through the machine as described above, each copy sheet being moistened on the side which comes into contact with the master sheet. A small amount of carbon is dissolved each time a copy sheet is fed through the machine and each copy sheet is a clear copy of the original.

The roller 51 has a lcorrugated outer surface as describedabove. This 'insures that there will be a rapid evaporation of any excess solvent which is deposited upon the roller 51 by the roller 60.

Referring'to'Fig. 4 it will be noted that when the lever 2N is in-position wherein it is shown in Fig. 4, the pin 208 ispositioned with respect to the pin 2li and the point of contact between the levers 205 and 200 so that the lever 2W 'will remain in the position wherein it-is shown until the operatorgrasps the handle 2 I3 and displaces the lever 2I0 in a counter'clockwise direction Fig. 4) against the action of the spring 202.

While I have shown and described certain embodiments of my invention, it is to be understood thatl it is` capable of many modifications. Changea therefore inthe construction'and arrangement may be made'without departing from the spirit and scope of the invention as disclosed' in the' appended claims, in which it is my intention to claim all novelty inherent in my invention as broadly as possible, inview of the prior I claim: l. A duplicating machine comprising a duplieating drum, means carried by the drum to clamp a mastersheet thereon, means for locking Athe drum against rotation, means operable While the drum is stationary for releasing said clamping means, and common means for actuating said lockin'gmeans and said releasing means.

2. A duplicating machine comprising a frame, a rotatable duplicating drum mounted in said frame, means carried by said drum for Vclamping against rotation, said last-mentioned means bethe` drum is stationary, and a lever,y pivoted on said'frame for actuating said locking means.

3. A duplicating machinecomprising a frame. a rotatable duplicating drum mounted insaid frame, means carried by said drum for clamping a master sheet thereto a leverv pivoted on said frame to lock said drum against rotation and to release said clamping means, and a second lever pivoted on saidframe for actuating the firstmentioned lever.

4. A duplicating machine comprising a frame, a rotatable duplicating drum mounted in said frame, means carried by said drum for clamping a master sheet thereto, -a lever pivot'ed on said frame to lock said drum against rotation and to release said clamping means, and means on said frame having a lost motion connection with said lever for actuating said lever.

5. A Aduplicating machine comprising ak frame, a rotatable duplicating drummounted in said frame, a shaft pivoted in said druml and carrying means for clamping a master sheet to' said drum.

a lever fixed to said shaft, a springv yieldably urging said shaft into va position wherein the clamping v'means will clamp a master sheet to the drum, a second lever pivoted to said frame and engageabie with the first-mentioned lever to displace it and release said clamping means against the' action of said spring, said second lever having means engageable with said drum to hold it against rotation, and a third lever pivoted to said frame for actuating said second lever.

6. A duplicating machine comprising a frame, a rotatable duplicating drum having a recess formed therein, a shaft Vpivoted in said drum,

means carried by said shaft for clamping a master sheet to said drum, a levervxedto said shaft, a spring yieldably urging said shaft into a position wherein the clamping means will clamp a master sheet to the drum, a second lever pivoted to said frame and engageable with the rstmentioned lever to displaceitaand release said clamping means against the action of said spring, said second lever having means engageabie with said recess to hold the drum against rotation, and means movably mounted onsaid frame for actuatingr said second lever.

7. A duplicatingmachine comprising a frame, -a rotatable duplicating drum vmounted in said frame, means carried by said drum for clamping a master sheet` thereto, manually operable means mounted on said frame for releasing said clamping means,a platen roller co-operating with said drum, means for moistening copy sheets advanced to said drum and said platen roller, a cam constrained to rotate with said drum, a roller riding on said cam, said cam and said roller co-operating to indicate to the operator when said drum is inthe proper position to have a copy sheet advanced thereto, and means actuated by said roller for controlling the supply of solvent to Vsaid moistening means,"

8. A duplicating machine comprising a frame, ay rotatable duplicating drum mounted in said frame, means carried by'said' drum for clamping a master sheet thereto, and means movably mounted in said `frame and .operable while the drum isstationary in one position to lock said drum against rotation and release' said .clamping means. f

9. nA duplicating machinecomprising, a frame, a rotatable duplicating drum mounted in said ing operable to release said clamping means while frame, means carried by said drum for clamping -a master sheet thereto, and means in said frame to lock said drum against rotation and to release said clamping means while the drum is locked against rotation, said locking and' releasing means comprising a lever pivoted on said frame and manually operable to actuate said locking and releasing means.

- 10. yA duplicating machine comprising a frame,

means carried by said drum for clamping a' master sheet thereto, and means movably mounted on said frame movable into position to release said clamping means when said drum is brought to a stop and heldstationary with said` clamping means in registry with said movably ,mounted means.

11. rA duplicating machine comprising'a frame, a rotatable duplicating drum mounted in said vframe, a platen roller co-operating with said duplicating drum to press copy sheets against it, means carried by said drum for clamping a masterfsheet thereto, and manually operable means movably mounted on said frame movable into position to release said clamping means when said drum' is brought to a stop `and held stationary with said clamping means in registry with said movably mounted means.

12. A duplicating machine comprising a frame, a rotatable duplicating drum mounted in said frame, a. platen'roller co-operating `with said duplicating drum' to press copy sheets against it,

means carried by said drum for clamping a al rotatable duplicating drum mounted in said frame, a platen roller co-operating with'said duplicating drum to press the copy sheets against it, a shaft pivotally mounted in said drum. clamp- V.ing means Vmounted on said shaft for clamping a master sheet to said drum. a lever secured t0 said shaft and a second lever mounted on said f frame for displacing the rst-mentioned lever to release the clamping means when the drum is brought to a stop and held stationary with the mst-mentioned lever in registry with said second lever. i

14. A duplicating machine comprising a frame, a rotatable duplicating drum mounted in said frame'I a shaft pivoted in said drum and carrying means for clamping a master sheet to said drum, a ylever fixed to said shaft, a spring yieldably urging said shaft into a position wherein the clamping means will clamp a master sheet to the drum, a second lever pivoted to said frame and engageable with the iirst-mentioned lever to displace it and release said clamping means against the action of said spring, said second lever having means engageable with said drum to hold it against rotation.

15. A duplicating machine comprising a frame, a rotatable duplicating drum mounted in said frame, means carried by said drum for clamping a. master sheet thereto, stop means on said drum, a lever pivoted on said frame and having means engageable with said stop means to lock said drum against rotation in either direction, said lever having means to release said clamping means while the drum is held stationary, and means on said frame having a lost motion con- 'nection with said lever -for actuating said lever. 16. A duplicating machine comprising a frame, a rotatable duplicating drum mounted in said frame, means carried by said drum for securing a master sheet thereto, means movablly mounted on said frame to engage said drum and hold it against rotation. said means including a mechanism `cooperating with said master sheet securing means to release the master sheet while-the drum is held by said means and adapted when the drum is released for renewed rotation to move said master sheet securing means automatically to its operative gripping position.

ALFRED. MARCHML a 

